An investigation into the stability and use of non-stoichiometric YBaCo4O7+δ for oxygen enrichment processes

Abstract

YBaCo4O7+δ has been reported to have a large oxygen capacity which can be accessed on practical timescales by both temperature and pressure swings below 400 °C. One potential use of this oxygen capacity is for oxygen enrichment of process gas streams for e.g. application in oxy-fuel combustion and auto-thermal reforming. In this work, YBaCo4O7+δ powders were produced by a solid state synthesis and their material properties studied with a view to use as a process stream oxygen enricher. The stability of the material as a function of temperature in both CO2 and reducing gases (CO and H2) was investigated. The kinetics of oxygen uptake and release was studied by following the response to swings in oxygen partial pressure (pO2) and temperature. To demonstrate the potential for employing this reversible oxygen capacity, the material was successfully used to supply oxygen into a gas stream with a pO2 of 0.31 bar after oxidation in an air stream (pO2 = 0.21 bar).

Atomic-level characterization of the oxygen storage material YBaCo4O7+δ synthesized at low temperature

“…Despite the great deal of attention that YBCO has gained in the last years, much research continues focusing on improving the oxygen storage property. 20,21 For functional materials, the property is generally governed by the size and shape of the particles, and their atomic arrangement, all of which are directly controlled by synthesis methods and conditions. For example, to enhance the oxygen absorption/desorption rate, a small particle size with a high surface area will be ideal.…”